Final answer:
Falconer's equation estimates the heritability of traits, which is how much phenotype variation is due to genetic differences. It applies to studying traits like eye color in Drosophila melanogaster. A cross between a white-eyed male and a heterozygous red-eyed female typically results in a 1:1 ratio of white-eyed to red-eyed offspring.
Step-by-step explanation:
Falconer's equation is a method used to estimate the heritability of a trait within a population. Heritability, in this context, refers to the fraction of phenotype variation that can be attributed to genetic differences among individuals. This concept is crucial for understanding how traits can evolve under natural selection. The equation is valuable as it provides insight into the role that genetics plays in the expression of phenotypes. In Drosophila melanogaster, for example, the heritability of eye color can be studied by examining the offspring resulting from crosses between different eye-colored flies.
When a cross is performed between a white-eyed male and a female that is heterozygous for red eye color, the resultant offspring ratio can be predicted using a Punnett square. Assuming the gene for eye color is located on the X chromosome and that white eyes are recessive, half of the male offspring would have white eyes and half of the female offspring would have red eyes since they would receive their father's X chromosome with the white-eye allele and their mother's X chromosome with either the red-eye allele or the white-eye allele.